After opening statements today in the trial of a 36-year-old West Goshen mother accused of plotting her husband's murder with her young lover, prosecutors presented the first witness: the victim's mother. Kathleen Barton testified that her son, Kevin Mengel Jr., had a "very up and down relationship" with his wife, Morgan M. Mengel, but, despite periodic separations, they always reunited for the sake of their three children. She said the last time she spoke with her son, June 17, 2010, he was looking forward to Father's Day. She said the two spoke daily, so when she didn't hear from him the following day, she was concerned. But she received assurances from her daughter-in-law, whom she loved, that she shouldn't worry. Kevin had "packed his clothes and left" but would return at some point, Barton said she was told. During sometimes tearful testimony, Barton said she began getting uncharacteristic texts from her son that indicated he wanted to be left alone. She said she begged him to call her: "I need to hear your voice telling me you're OK." But the strange texts continued: "I am doing what I need to do ... You just keep pushing and it's not helping." Prosecutors allege the sender of the texts was Morgan Mengel, who didn't want her mother-in-law's suspicions to attract police. Initially, they didn't. "The police just thought I was a neurotic mother," Barton testified. But she had support from family members and friends, and as days went by, they staked out the West Goshen residence the Mengels had shared and learned that Stephen Shappell, a 21-year-old employee of the Mengels' landscaping business, had moved in with Morgan Mengel. On June 25, 2010, police were informed that Morgan Mengel and Stephen Shappell had packed up belongings and appeared poised to flee. The pair had killed Kevin Mengel and were planning to run away together, prosecutors said. And when police arrived, Shappell saw an opportunity and fled alone. He was later apprehended in Colorado. He has since pleaded guilty and will testify against his former lover during the trial, which is expected to last a week. Prosecutors Patrick Carmody and Deborah Ryan allege that Morgan Mengel manipulated Shappell, goading him to commit the murder. Defense attorney Jack McMahon contends the killing was entirely Shappell's doing so he could impress his paramour. At the conclusion of today's dramatic testimony, which also included interviews between Morgan Mengel and West Goshen Det. David Maurer, Barton crossed paths with Morgan Mengel's mother in the hallway outside Judge Thomas G. Gavin's courtroom. The two grandmothers spoke briefly and then hugged, unleashing a flood of tears. For more information on today's trial, read tomorrow's Inquirer or visit philly.com.